Optimal timing of aspirin discontinuation with ticagrelor monotherapy in acute coronary syndrome: a post hoc comparative analysis from the TICO and T-PASS trials

BACKGROUND: Ticagrelor monotherapy following abbreviated dual antiplatelet therapy (DAPT) is an emerging strategy for patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). However, the timing of aspirin discontinuation has not been directly compared in this setting. AIMS: We aimed to compare the clinical outcomes of aspirin discontinuation within 1 month versus at 3 months after PCI in patients with ACS. METHODS: This post hoc analysis used individual patient-level data from the TICO and T-PASS trials, which exclusively enrolled patients with ACS undergoing PCI. Of 2,953 patients who received ticagrelor monotherapy after abbreviated DAPT, 1,426 discontinued aspirin within 1 month and 1,527 at 3 months. After propensity score matching, 2,248 patients were included in the final analysis. The primary endpoint was a composite of all-cause death, myocardial infarction, stent thrombosis, ischaemia-driven target vessel revascularisation, stroke, and major bleeding at 1 year. RESULTS: The primary endpoint occurred less frequently in the <1-month group than in the 3-month group (3.2% vs 5.6%; hazard ratio [HR] 0.56, 95% confidence interval [CI]: 0.37-0.84; p=0.005). Ischaemic event rates were comparable (2.2% vs 2.3%; HR 0.86, 95% CI: 0.55-1.65; p=0.863), whereas major bleeding was significantly lower in the <1-month group (1.1% vs 3.3%; HR 0.32, 95% CI: 0.17-0.61; p<0.001). Landmark analysis showed that event rates diverged primarily within the first 90 days, with no significant heterogeneity between the early and late periods. CONCLUSIONS: Aspirin discontinuation within 1 month followed by ticagrelor monotherapy improved net clinical outcomes compared with 3-month discontinuation, primarily by reducing major bleeding without increasing ischaemic risk. CLINICALTRIALS: gov: NCT02494895 (TICO), NCT03797651 (T-PASS).